In $2010$ Casey made a taxable gift of $5\mathrm{.}1$ million to both Stephanie and Linda $($a total of$10\mathrm{.}2$ million in taxable gifts$).$ Calculate the amount of gift tax due this year and Casey's unused applicable credit under the following alternatives. $($Refer to Exhibit $25-1$ and Exhibit $25-2.)$ Note: Enter your answers in dollars, not millions of dollars. Leave no answer blank. Enter zero if applicable. a$.$ This year Casey made a taxable gift of $1$ million to Stephanie. Casey is not married, and the $2010$ gift was the only other taxable gift he has ever made. Gift tax due

Unused applicable credit

EXHIBIT $25-1$ Unified Transfer Tax Rates$**$The estate tax was optional for decedents dying in $2010.$ In lieu of the estate tax, executors could opt to have the adjusted tax basis of the assets in the gross estate carry over to the heirs of the decedent. The applicable credit and exemption are zero for taxpayers who opt out of the estate tax in $2010.$